Download SERVICE MANUAL RIVA COMPACT M90E.24S M90E.28S

Wall hung, fan flue, room sealed gas boiler
SERVICE MANUAL
RIVA COMPACT
Models:
G.C. Appl. No.
M90E.24S
M90E.28S
M90E.32S
47--970--17
47--970--18
47--970--21
Leave this manual adjacent to the gas meter
Biasi U.K. Ltd
Unit 31/33, Planetary Road
Industrial Estate, Neachells Lane
Willenhall, Wolverhampton WV 13 3XB
Technical helpline: 01902 304 400
Web site: www.biasi.co.uk
Table of contents
1
1.1
1.2
Overall information . . . . . . . . . . . . . . . . . .
Overall View . . . . . . . . . . . . . . . . . . . . . . . . .
Hydraulic diagram . . . . . . . . . . . . . . . . . . . .
2
2
2
2
2.1
2.2
2.3
2.4
2.5
2.6
General access and emptying
hydraulic circuits . . . . . . . . . . . . . . . . . . . .
Nomenclature . . . . . . . . . . . . . . . . . . . . . . . .
Body panels . . . . . . . . . . . . . . . . . . . . . . . . .
Control panel . . . . . . . . . . . . . . . . . . . . . . . .
Access to the sealed chamber . . . . . . . . .
Emptying the primary circuit . . . . . . . . . . .
Emptying the d.h.w. circuit . . . . . . . . . . . .
3
3
3
3
4
4
4
3
3.1
3.2
3.3
Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring diagram . . . . . . . . . . . . . . . . . . . . . . .
Functional flow diagrams . . . . . . . . . . . . . .
Circuit voltages . . . . . . . . . . . . . . . . . . . . . .
5
5
7
8
4
Fault finding . . . . . . . . . . . . . . . . . . . . . . . . 11
5
5.1
5.2
5.3
Primary heat exchanger . . . . . . . . . . . . . .
Characteristics . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Cleaning . . . . . . . . . . . . . . . . . . . . . . . . . . . .
6
6.1
6.2
D.h.w. heat exchanger . . . . . . . . . . . . . . . 14
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
13
13
13
13
7
7.1
7.2
7.3
Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . .
15
15
15
15
8
8.1
8.2
8.3
8.4
Three way diverter valve . . . . . . . . . . . . .
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal of the electric actuator . . . . . . . .
Removal of the diverter group
and its internal parts . . . . . . . . . . . . . . . . . .
16
16
16
16
9
9.1
9.2
9.3
9.4
9.5
9.6
9.7
9.8
9.9
9.10
9.11
Electronic control p.c.b. . . . . . . . . . . . . . .
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Selection and adjustment devices . . . . . .
Checking the temperature . . . . . . . . . . . . .
Operation/Service lamps . . . . . . . . . . . . . .
Dip---switch selectors . . . . . . . . . . . . . . . . .
Setting jumpers . . . . . . . . . . . . . . . . . . . . . .
Ignition gas pressure adjustment . . . . . . .
Max c.h. power adjustment . . . . . . . . . . . .
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal of the electronic control p.c.b . .
Thermal control in the ” ” mode . . . . . .
18
18
18
18
19
20
21
21
21
21
21
23
9.12
Thermal control in the ”
10
10.1
10.2
Full sequence ignition device . . . . . . . . . 24
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
17
” mode . . . . . . 23
10.3
10.4
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Ignition and control sequence . . . . . . . . . . 25
11
11.1
11.2
11.3
11.4
11.5
11.6
Modulating gas valve . . . . . . . . . . . . . . . .
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nomenclature of the parts . . . . . . . . . . . . .
Adjustment . . . . . . . . . . . . . . . . . . . . . . . . . .
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal of the on---off operator coils . . .
Removal of the gas valve . . . . . . . . . . . . . .
26
26
26
26
27
27
27
12
12.1
12.2
12.3
Primary circuit flow switch . . . . . . . . . . .
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . .
28
28
28
28
13
Expansion vessel and
temperature-- pressure gauge . . . . . . . .
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal of the expansion vessel . . . . . . .
Removal of the temperature---pressure
gauge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
13.1
13.2
13.3
13.4
14
14.1
14.2
14.3
14.4
14.5
29
29
29
29
29
30
30
30
30
30
14.6
D.h.w. flow switch, filter and flow limiter
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Nomenclature and location of parts . . . . .
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal of the flow switch sensor . . . . . .
Removal of the flow switch group
and d.h.w. circuit filter . . . . . . . . . . . . . . . . .
Flow limiter . . . . . . . . . . . . . . . . . . . . . . . . . .
15
15.1
15.2
15.3
Temperature probe . . . . . . . . . . . . . . . . . .
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . .
32
32
32
32
16
16.1
16.2
By -- pass valve . . . . . . . . . . . . . . . . . . . . . . 33
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33
17
17.5
Fan, venturi device and
Air pressure switch . . . . . . . . . . . . . . . . . .
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal of the Fan . . . . . . . . . . . . . . . . . . .
Inspection and removal of the venturi
device . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal of the Air pressure switch . . . . .
18
18.1
18.2
18.3
Ignition and detection electrodes . . . . .
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . .
36
36
36
36
19
19.1
19.2
19.3
Safety thermostat . . . . . . . . . . . . . . . . . . .
Function . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removal . . . . . . . . . . . . . . . . . . . . . . . . . . . .
38
38
38
38
20
Short spare parts list . . . . . . . . . . . . . . . . 40
17.1
17.2
17.3
17.4
30
31
34
34
34
35
35
35
1
1
Overall information
1.1
Overall View
Air pressure
switch
Fan
Main heat
exchanger
Safety
thermostat
Burner
Expansion
vessel
Combustion
chamber
Ignition
electrodes
Detection
electrode
Diverter valve
Automatic
air release
valve
Main circuit
flow switch
D.h.w. temp.
probe
Pump
Gas valve
D.h.w
flow switch
Control
panel
1.2
Hydraulic diagram
Central heating (c.h.) operation
C.h.
water return
2
D.h.w.
heat exchanger
C.h.
water flow
Domestic hot water (d.h.w.) operation
D.h.w.
inlet
D.h.w.
outlet
2
General access and emptying
hydraulic circuits
A
2.1
Nomenclature
1
2
6
Fig. 2
3
To remove the side panels loosen the screws B and C
(Fig. 3), bring the base of the panels away from the
boiler and lift them, freeing them from the top hooks.
D
5
4
Fig. 1
1
Right side panel
2
Front panel
3
Control panel lid
4
Control panel cover
5
Service panel
6
Left side panel
B
C
Fig. 3 --- bottom view of the boiler
2.3
2.2
Body panels
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
For the most part of the check and maintenance operations it is necessary to remove one or more panels of
the case.
The side panels can be removed only after the removal
of the front panel.
To remove the front panel remove screws A (Fig. 2), lift
the panel and remove it.
Control panel
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
To gain access to the parts located inside the control
panel proceed as follows:
1
Remove the front panel of the case
2
Loosen the screws B and C (Fig. 3).
3
Remove the screws D
4
Move the lower part of the side panels as indicated in Fig. 4 and pull the control panel.
When completely pulled out, the panel can rotate
45° downwards to facilitate the service operations on the internal parts.
3
General access and emptying hydraulic circuits
To gain access to the parts contained in the sealed
chamber it is necessary to remove the lid of the sealed
chamber.
For this purpose, remove the front and side panels of
the case, remove the screws G as indicated in Fig. 6
and remove the lid.
2.5
1
Fig. 4
Emptying the primary circuit
Close the c.h. circuit flow and return cocks H.
(Fig. 7).
Remove the screws E and remove the service
panel (Fig. 5);
To gain access to the electronic regulation PCB
and the full sequence ignition device remove the
screws F and remove the control panel lid
(Fig. 5);
5
6
J
H
F
E
H
Fig. 7 --- bottom view of the boiler
F
2
Remove the front and right panels of the boiler.
3
Open the drain tap I (Fig. 8) until the boiler is completely emptied.
4
Close drain tap again once the emptying has
been completed.
Fig. 5
2.4
Access to the sealed chamber
G
G
I
Fig. 8
2.6
Fig. 6
4
Emptying the d.h.w. circuit
5
Close the d.c.w. inlet cock J (Fig. 7);
6
Open one or more hot water taps until the boiler
has been completely emptied.
3
Diagrams
3.1
Wiring diagram
Wiring diagram for boiler equiped with full sequence ignition device type: Bertelli & Partners FM30
1
rd
bu
Fan
Ignition Flame detection
electrodes
electrode
Air pressure
switch
ye
M
~
wh
gnye
og
vt
Safety
thermostat
bn
bu
NO
NC
bk
COM
gnye
gnye
gnye
gnye
2
gy
bn
3
Electric supply
terminal block
gnye
bu
bu
External controls
terminal block
gnye
bu
bn
bk
rd
bn
bu
bk
bn
rd
bk
rd
wh
bu
gy
bk
Electronic
control p.c.b.
gnye
gnye
ye
wh
og
vt
bk
bu
bn
bk
bu
bk
bu
bn
bk
rd
bk
bu
bu
gy
rd
gnye
bn
gnye
bn
bu
bn
bk
bu
bu
bk
bn
rd
Full sequence
ignition device
bk
gy
bk
t
D.h.w. temperature
probe NTC
bn = brown
bu = blue
bk = black
wh = white
rd = red
gy = grey
gn = green
ye = yellow
vt = violet
og = orange
gnye = green/yellow
bu
D.h.w. flow
switch
bk
bu
Primary circuit C.h. temperature
flow switch
probe NTC
bu
bk
gnye
rd
1
2
3
wh
t
bk
bk
gnye
bn
bu
bk
rd
rd
M
~
M
~
Three way
diverter valve
Pump
bu
gnye
bn
gnye
Modulating
gas valve
rd
bk
wh
gn
Time switch
5
Diagrams
Wiring diagram for boiler equiped with full sequence ignition device type: Honeywell FPLD
1
rd
bu
Fan
Air pressure
switch
ye
M
~
wh
gnye
og
vt
Safety
thermostat
Ignition Flame detection
electrodes
electrode
bn
bu
NO
NC
bk
COM
gnye
gnye
gnye
gnye
2
gy
bn
3
Electric supply
terminal block
gnye
bu
bu
External controls
terminal block
gnye
bu
bn
bk
rd
bn
bu
bk
bn
rd
bk
rd
wh
bu
gy
bk
Electronic
control p.c.b.
bn
gnye
gnye
ye
wh
og
vt
bk
bu
bu
bk
bn
bk
bu
bn
bk
rd
bk
bu
bu
gy
rd
gnye
bn
gnye
bu
bn
bk
bu
bu
bn
bu
bk
rd
rd
bk
bk
bu
bk
bu
t
t
DHW temperature
probe NTC
DHW flow
switch
Primary circuit
flow switch
CH temperature
probe NTC
Three way
diverter valve
bk
gy
bu
bn
gnye
wh
1
2
3
rd
bk
Full sequence
ignition device
rd
bn
bk
gnye
M
~
M
~
bu
gnye
bn
gnye
Modulating
gas valve
Pump
rd
bk
wh
bn = brown
bu = blue
bk = black
wh = white
rd = red
gy = grey
gn = green
ye = yellow
vt = violet
og = orange
gnye = green/yellow
6
gn
Time switch
Diagrams
3.2
Functional flow diagrams
General layout
J1--- 1
Fuse 1,6A T
Electronic
control p.c.b.
(low voltage section)
PTC
Transformer
L
J3--- 5
J3--- 4
J3--- 3
Three way
diverter valve
J1--- 2
N
Pump
J3--- 1
J3--- 2
J2--- 5
J2--- 4
Full sequence
ignition device
Heat request on d.h.w.
Electronic
control p.c.b.
(low voltage section)
J1--- 1
Fuse 1,6A T
PTC
Transformer
L
J3--- 5
J3--- 4
J3--- 3
Three way
diverter valve
J1--- 2
N
Pump
L --- LINE
J3--- 1
J3--- 2
J2--- 5
J2--- 4
N --- NEUTRAL
ACTIVE CIRCUIT
INACTIVE CIRCUIT
Full sequence
ignition device
Heat request on c.h.
Electronic
control p.c.b.
(low voltage section)
J1--- 1
Fuse 1,6A T
PTC
Transformer
L
J3--- 5
J3--- 4
J3--- 3
Three way
diverter valve
J1--- 2
N
Pump
J3--- 1
J3--- 2
J2--- 5
J2--- 4
Full sequence
ignition device
7
Diagrams
3.3
Circuit voltages
Diagrams for boiler equiped with full sequence ignition device type: Bertelli & Partners FM30
during c.h. or d.h.w. operation
Electrical voltages with burner on
only during c.h. operation
230~
0
230~
230~
230~
Pump
0
3 way diverter valve
Supply network
only during d.h.w. operation
230~
Full sequence
Ignition device
230~
230~
230~
0
0
Modulating
Gas valve
0
Safety
thermostat
Fan
230~
Air
pressure
switch
0
Electronic
control p.c.b.
Electronic
control p.c.b.
230~
8
Diagrams
Diagrams for boiler equiped with full sequence ignition device type: Honeywell FPLD
during c.h. or d.h.w. operation
Electrical voltages with burner on
only during c.h. operation
230~
0
230~
230~
230~
Pump
0
3 way diverter valve
Supply network
only during d.h.w. operation
230~
Full sequence
Ignition device
230~
230~
230~
0
0
Modulating
Gas valve
0
Safety
thermostat
Fan
230~
Air
pressure
switch
0
Electronic
control p.c.b.
Electronic
control p.c.b.
230~
9
Diagrams
10
11
J
By pressing the reset push--- button the
boiler starts the ignition cycle.
The burner lights on, the ignition
sparks continue and the boiler locks
again.
--(5)
D.h.w. heat exchanger
8.2
Diverter valve
D.h.w. circuit
C.h. circuit
9.9
J
J
D.h.w. flow switch
The boiler lights for a short while on
c.h.
Normal operation on d.h.w. function.
J
Fuse (regulation p.c.b.)
J
J
7.2
Pump
6
Regulation p.c.b.
The boiler doesn’t control the d.h.w.
temperature.
Turning the d.h.w. temp. adjustment
knob hasn’t effect on the modulation of
the flame.
The boiler operates correctly on c.h.
The burner doesn’t light either in c.h.
or d.h.w. mode.
Fan doesn’t turn.
The burner doesn’t light either in c.h.
or d.h.w. mode.
Fan turn.
J
By pressing the reset push--- button the
boiler starts the ignition cycle.
The burner doesn’t light on, the ignition sparks continue and the boiler
locks again.
J
J
J
Power supply line
J
--(3)
Gas supply line
By pressing the reset push--- button the
boiler turns on and operates correctly.
The boiler does not start either in c/h
or d.h.w. mode.
Fan still.
Defect
#
--(4)
Flue pipes
--(2)
10.2
Full sequence device
J
J
J
Gas valve (on--- off operators)
J
Gas valve (modulating operator)
J
(7)
12.2 14.5
Main circuit flow switch
J
15.2
Main circuit temp. probe
J
J
D.h.w. temp. probe
J
J
16
By--- pass valve
J
17.2
Fan and venturi device
J
J
Air pressure switch
J
J
18.2
Ignition electrode
J
J
J
Detection electrode
D.h.w. filter
11.4
19.2
J
J
Safety thermostat
Section of the manual !
(note ref. in brackets)
J
J
--(9)
--(8)
Injectors
Components to check
Expansion vessel
Fault finding
---
---
Safety valve
4
Appliance operation
lamp green (1)
ON --- fast pul
ulses
ON --- fasst pulses
OFF
Lock--- out signal lamp red
OFF
ON
OFF
Pressure gauge
Function selectors (reg. p.c.b)
---
---
Appliance operation
lamp green (1)
ON ----- norm
mal pulsess
---
---
For details see section 9.4 of this manual.
Further useful information can be obtained by switching
the electronic control p.c.b. in the service operation mode
(see section 9.4 of this manual).
Check for 230V~ between line (L) and neutral (N)
Verify the integrity of supply cable, plug and external fuses.
Check the polarity of line and neutral connection
Verify the soundness of the gas supply pipe, the position of
2
3
Water leaks from the safety valve when
the boiler is off.
Water leaks from the safety valve during operation on c/h
Low d.h.w. flow rate
Poor d.h.w. temperature
The boiler operates correctly but the
gas pressure to the burner remains at
minimum.
Noisy bolier
Incorrect modulation
J
Power supply line
J
C.h. circuit
J
D.h.w. flow switch
J
9.9
Regulation p.c.b.
J
J
J
J
Function selectors (reg. p.c.b)
J
J
J
J
12.2 14.5
Gas valve (on--- off operators)
Full sequence device
Fuse (regulation p.c.b.)
Check for soundness and absence of obstructions. Verify that
the flue terminal is correctly installed (see clearances) and ensure that exhaust gas is not sucked back by the boiler.
Check for soundness of the circuit and verify its correct filling
(see also installation manual).
5
J
D.h.w. filter
10
8
9
7
6
J
(10)
15.2
16
17.2
Fan and venturi device
19.2
--(8)
Injectors
J
J
--(9)
Expansion vessel
Ignition electrode
Air pressure switch
By--- pass valve
D.h.w. temp. probe
Main circuit temp. probe
J
J
J
J
---
---
A jammed by--- pass could cause the over--- heating of the main
circuit and the intervention of the safety thermostat.
Check the minimum gas pressure at the outlet test point of the
gas valve (see sect. 11.3) and compare it with the value given
on the installation booklet.
Verify the cleanness of injectors.
Check the pressurization of the expansion vessel. Refer to the
installation manual for proper values.
d.h.w. pressure too high or flow rate too high. If necessary insert a flow rate limiter (14.6).
J
18.2
Detection electrode
11.4
Safety valve
Components to check
10.2
Gas valve (modulating operator)
stop valves.
Check the gas pressure at the inlet test point of the gas valve
(see sect. 11.3) with the boiler at rest and during operation and
compare it with the values given on the installation booklet.
J
J
8.2
Main circuit flow switch
4
J
J
D.h.w. circuit
J
7.2
6
D.h.w. heat exchanger
On c/h mode the temperature of the
main circuit reaches 75°C and the c/h
system does not heat.
The boiler operates correctly on d.h.w.
mode.
Gas supply line
1
Note
Lock--- out signal lamp red
OFF
F
--(5)
Pump
J
--(3)
Diverter valve
The boiler does not supply d.h.w. (cold
water from the tap).
Regular operation in c/h mode even
during a drawing off d.h.w.
Defect
#
--(4)
Flue pipes
--(2)
Safety thermostat
Section of the manual !
(note ref. in brackets)
Pressure gauge
12
5
Primary heat exchanger
5.1
Characteristics
C
G
The primary heat exchanger A in Fig. 9 has the function
of transferring heat produced from combustion of the
gas to the water circulating in it.
F
B
A
E
D
Fig. 11
5
Unscrew the connection H (Fig. 12), lift the pipe
I and rotate it right then move it downwards freeing it from the heat exchanger connection.
6
Remove the motor of the three way diverter valve
(see section 8.3).
Completely unscrew the connection J and rotate
the pipe K. downwards freeing it from the heat exchanger connection.
Remove the heat exchanger by sliding it forwards.
Reassemble the boiler carrying out the removal
operations in reverse order. Fit the clips F with
the arrow pointing upwards as illustrated in
Fig. 11.
7
8
9
Fig. 9
The hydraulic circuit is composed of 8 elliptical pipes
connected in parallel (Fig. 10).
I
H
J
Fig. 10
5.2
K
Removal
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
Empty the primary circuit of the boiler.
2
Remove the case panels and the sealed chamber
lid (see section 2).
3
Remove the combustion chamber lid B by unscrewing the screws C (Fig. 11).
3b
For model M90E.28S and M90E.32S only, remove the screw D and the plate E.
4
Remove the clips F and the safety thermostat G.
It is not necessary to disconnect it from the wiring.
Fig. 12
5.3
Cleaning
If there are deposits of soot or dirt between the blades
of the heat exchanger, clean with a brush or non---metallic bristle brush.
In any case, avoid any actions that can damage the protective varnish with which the exchanger has been covered.
Warning: After cleaning or replacement as
detailed above refer to section Combustion
analysis check in the chapter Maintenance of
the installation instructions manual.
13
6
D.h.w. heat exchanger
6.1
Function
6.2
The d.h.w heat exchanger A in Fig. 13 allows the instantaneous transfer of heat from the primary hydraulic circuit to the water destined for d.h.w use.
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
2
3
A
Removal
4
Remove the front and right hand side panels of
the case.
Empty the primary circuit and the d.h.w circuit of
the boiler.
Remove the motor of the three way diverter valve
(see section 8.3).
Completely unscrew the two Allen key screws B
(Fig. 15) which hold the exchanger to the brass
groups.
B
Fig. 15
5
Fig. 13
The schematic structure is shown in Fig. 14.
Reassemble the d.h.w. heat exchanger carrying out the
removal operations in the reverse order.
Attention. When reassembling the exchanger be
sure to put the off center location/securing pin indicated in Fig. 16 towards the left side of the boiler.
Primary hydraulic circuit
Domestic hot water circuit
Fig. 14
14
Move the exchanger towards the rear of the boiler
and extract it.
Fig. 16
7
Pump
7.1
Function
The pump A in Fig. 17 has the function of making the
water in the main circuit circulate through the main heat
exchanger and therefore through the c.h. system (during the c.h. function) or through the secondary heat exchanger (during the d.h.w. function).
n
Check that the impeller is integral with the rotor.
With the boiler off remove the front and right hand side
case panels, lower the control panel and empty the primary circuit.
Remove the pump head by undoing the screws which
hold it to the pump body and check that the impeller is
firmly joined to the rotor.
7.3
Removal
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
A
1
2
3
4
5
Remove the front and right hand side case panels
Empty the primary circuit of the boiler.
Extract and lower the control panel.
Disconnect the connector B (Fig. 18).
Unscrew the connection C and move the pipe upwards freeing it from the outlet port of the pump.
Remove the fork D and the capillary pipe
Remove the locking plate E right (Fig. 18).
6
7
C
B
D
Fig. 17
7.2
E
Checks
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
n
Check that the pump is not seized and that the
movement of the rotor is not subject to mechanical impediments.
Fig. 18
8
9
Loosen the connection F, remove the fork G and
the pipe H.
Unscrew the two screws I that hold the pump on
the frame (Fig. 19)and remove the pump towards
the front of the boiler.
With the boiler off, remove the front panel. Remove the
air release plug of the pump and turn the rotor with a
screwdriver.
n
G
H
Check the electrical continuity.
F
With the boiler off, remove the front panel and disconnect the connector B (Fig. 18).
Measure the electrical resistance between the pump
supply connections.
Electrical resistance of the windings (at ambient temperature) must be about 230 W
n
Check the absence of starting defects.
With the boiler off remove the front case panel.
Remove the air release plug from the pump. Start the
boiler and with a screwdriver, turn the rotor in the direction of the arrow. If there is a defect in starting, the rotor
will begin to turn normally only starting it manually.
I
Fig. 19
Reassemble the pump carrying out the removal operations in the reverse order. When reassembling the
pump, check the correct location of the O---ring gasket
in the inlet port of the pump that seals the connection
between the pump and the brass group .
15
8
Three way diverter valve
8.1
Function
B
Spindle B
not visible
1
2
3
The diverter valve A (Fig. 20) has the function of modifying the hydraulic circuit of the boiler by means of an
electric command given by the electronic control p.c.b.
in order to send the water that exits the primary heat exchanger towards the c.h. system or towards the d.h.w.
heat exchanger.
9,4 Kohm
bn
0V
bu
bk
Open circuit
230 V
bn = brown
bu = blue
bk = black
Fig. 21 --- D.h.w. mode
B
1
2
3
Spindle B
visible
Open circuit
n
Checks
Check the electrical continuity
Fig. 21 indicates the relationship between the electric
command coming from the electronic control p.c.b.
and the position of the actuator B (brass spindle) when
the boiler operates in d.h.w. mode.
Fig. 22 indicates the relationship between the electric
command coming from the electronic control p.c.b.
and the position of the actuator B (brass spindle) when
the boiler operates in c.h. mode.
In both figures the relationship between the position of
the actuator and the resistance of the motor windings
(the motor must be disconnected from the wiring) is
also given.
16
bn
bu
230 V
Fig. 20
8.2
9,4 Kohm
bk
bn = brown
bu = blue
bk = black
0V
A
Fig. 22 --- C.h. mode
8.3
Removal of the electric actuator
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
2
3
Remove the front case panel.
Disconnect the connectors C (Fig. 23).
Remove the fixing spring D and remove the
actuator E.
Reassemble the actuator carrying out the removal operations in the reverse order.
When reassembling the actuator, refer to Fig. 21
or to the wiring diagram in section 3.1 for the correct wiring connection.
Three way diverter valve
9
E
C
Unscrew the screw L and remove the diverter
group.
D
J
K
Fig. 23
L
8.4
Removal of the diverter group and its
internal parts
1
2
Remove the front and both side case panels.
Empty the primary circuit and the d.h.w circuit of
the boiler.
Remove the electric actuator (see section 8.3).
Remove the fixing spring F (Fig. 24) and remove
the primary circuit flow switch G.
Disconnect the c.h. temperature probe H.
Unscrew the connector I, the c.h. flow connector
and the d.h.w. outlet connector.
3
4
5
6
I
Fig. 25 Rear view of the boiler
10
Refer to the exploded view in Fig. 26 to remove
the internal parts of the three way diverter valve.
F
H
G
Fig. 24
7
8
Remove the d.h.w. heat exchanger (see section
6.2).
Remove the fork J and move away the pipe K
(Fig. 25).
Fig. 26
11
Reassemble the diverter group carrying out the
removal operations in the reverse order.
17
9
Electronic control p.c.b.
9.1
Function
Inlet Information
On the Electronic control p.c.b.......
Function control*
C.h. temperature adjustment*
D.h.w. temperature adjustment*
Function dip---switches
Max. c.h. gas pressure adjustment
Ignition gas pressure adjustment
Boiler reset button*
*control panel fascia
From other boiler devices....
C.h. temperature probe NTC
D.h.w. temperature probe NTC
D.h.w. flow switch
Primary circuit flow switch
Room thermostat (if fitted)
Time switch
Flame presence signal*
*from the full sequence ignition device
The fundamental function of the Electronic control
p.c.b. is that of controlling the boiler in relation to the external needs (i.e. heating the dwelling or heating the
water for d.h.w. use) and operating in order to keep the
temperature of the hydraulic circuits constant.
This is obviously possible within the useful power and
maximum working temperature limits foreseen.
Generally, the Electronic control p.c.b. receives inlet information coming from the boiler (the sensors) or from
the outside (knobs, room thermostat, etc.), processes
it and consequently acts with outlet commands on
other components of the boiler (Fig. 27).
9.2
Selection and adjustment devices
On the Electronic control p.c.b. several selection, adjustment and protection devices are located. (Fig. 28).
Some of these devices are directly accessible by the
user (function control, temperature adjustment potentiometers etc.) others are accessible by removing the
service panel or the control panel lid.
14
1
13
12
2
11
10
9
8
7
6
5
4
3
Fig. 28
Outlet command
Pump
Three way diverter valve
Full sequence ignition device
Modulation operator
Appliance operation light*
Operation/service lamps
Lock ---out signal lamp*
*control panel fascia
Fig. 27
18
1
2
3
4
5
6
7
8
9
10
11
12
13
14
9.3
J3 connector
J2 connector
Lock ---out signal lamp
Boiler reset button
Function control / C.h. temperature adjustment
D.h.w. temperature adjustment
Service lamps (service mode)
Appliance operation lamp (normal use mode)
Dip---switch selectors
Setting jumpers
Ignition gas pressure adjustment (ACC.)
Maximum c.h. gas pressure adjustment (RISC.)
J1 connector
Fuse 1,6 A T
Checking the temperature
The Electronic control p.c.b. makes it possible to separately adjust the c.h. water flow temperature and d.h.w.
outlet temperature.
The temperature of the water is converted into an electric signal by means of temperature probes.
Electronic control p.c.b.
The user, setting the desired temperature with the control panel knobs operates the variable elements (5 and
6 in Fig. 28) of the electronic control p.c.b.
If the power requested is lower than 40% of the maximum power output then control is achieved by switching ON the burner at minimum power, then switching
OFF (ON/OFF function). If the power requested is
higher, then the burner is switched ON at maximum
power and will control by modulating to 40% of the
maximum power output.
During the c.h. operation (Fig. 29), the signal coming
from the c.h. temperature probe is compared to the signal given by the control panel through the adjustment
made by the user (knob ). The result of such a comparison operates the modulation of the gas valve,
consequently changing the useful output of the boiler.
75 ° C
Fig. 30
Normally, the result of the comparison between these
two signals directly operates the adjustment elements
of the gas valve modulation device, adjusting the useful
output generated in order to stabilize the temperature
of the exiting water.
If during the d.h.w. mode operation, the temperature of
the primary circuit goes over 75°C, the useful output is
automatically reduced so that the primary circuit cannot reach excessive temperatures.
function and in
funcThe control sequences in
tion are illustrated in detail in sections 9.11 and 9.12.
9.4
Fig. 29
When the boiler functions in d.h.w. (Fig. 30), the signal
coming from the d.h.w. temperature probe is compared
with the signal given by the control panel through the
adjustment made by the user (knob
).
Operation/Service lamps
The Electronic control p.c.b. is provided with three
lamps (L.E.D. indicators) 7 in Fig. 28 that give optical information during the normal operation of the boiler or
for service purpose.
f
Normal operation
Only the green lamp on the left is directly visible on the
control panel fascia and it gives information during the
normal operation of the boiler. The other two lamps are
normally switched off.
19
Electronic control p.c.b.
The following table gives the relationship between the
visible lamp indication and its meaning.
Normally operating boiler
Boiler in stand --- by condition.
(function control in
position).
A short pulse every 4 seconds
C.h. operation
D.h.w. operation
Anti--- freeze system active.
Boiler ON condition
(function control in
position)
Frost protect operation
or
D.h.w. operation
Excessive temperature on primary circuit
1 second ON 1 second OFF
Faulty boiler or irregular
operation as:
Very fast pulses (4 per second)
Faulty c.h. temperature probe NTC
--- Empty primary circuit
Faulty d.h.w temperature probe NTC
--- No primary circuit flow
--- Lack of burner ignition
Faulty primary circuit
(no water or absence of flow)
--- Excessive temperature in
the primary circuit.
Lack of burner ignition (no ignition signal from
the full seqence ignition device)
--- Dip --- switch 3 left in the OFF
position
--- Faulty temperature probe
f
Ignition gas pressure adjustment
Service operation
Minimum gas pressure adjustment
With the boiler switched ON (
or ), by moving and
re---setting to its original position any of the function selectors 9 (Fig. 28), the Electronic control p.c.b. goes
into service operation mode and all the lamps (7 in
Fig. 28) are then activated.
To reset the Electronic control p.c.b. to the normal operation it is necessary to turn the knob to the position
or switch off the boiler for a short while at the fused spur
isolation switch.
The following table gives the relationship between each
of the possible lamp combinations and their meaning.
Lack of power supply or fauly electronic
control p.c.b. *
Fauly electronic control p.c.b. *
Lamp
OFF
Lamp
ON
Flashing lamp, alone
or simultaneously
with an other lamp.
Flashing lamp,
alternate with
another lamp.
* These conditions are normal only for a short time when the
power supply is applied to the boiler.
If permanent they indicate a faulty p.c.b.
9.5
Dip---switch selectors
The function selectors 9 (Fig. 28 and Fig. 31) are microswitches with which it is possible to select the various
boiler control function modes.
In Fig. 31 the selectors are illustrated in the configuration in which the boiler is set in the factory (natural gas
boiler).
Minimum gas pressure adjustment
Gas conversion
Ignition gas pressure adjustment
Reignition frequency
1
2
3
4
ON (1)
OFF (0)
9
Fig. 31
f
Selector 1
This forces the boiler to operate at the minimum gas
pressure in order to allow the adjustment of the minimum gas pressure at the burner (on the modulation operator of the gas valve).
20
Electronic control p.c.b.
After any adjustment operation the selector has to be
brought back to the normal position (ON).
f
Selector 2
This selects the boiler functions on the basis of the type
of gas used.
It allows the selection of the maximum supply current
given to the modulator device.
To set selector 2 correctly follow the table in Fig. 32.
Gas supply
Position of selector
Approx. Max current
through the modulator device
Natural gas
On
120 mA
L.P.G.
Off
165 mA
Fig. 32
f
Selector 3
This forces the functioning of the boiler in order to allow
the optimal gas pressure at the burner to be adjusted
during the ignition phase.
The adjustment (see section 9.7) is done by means of
the potentiometer ”11” marked “ACC” (Fig. 28 on page
18).
After the adjustment operations bring the selector back
to the normal position (ON).
ON (1)
OFF (0)
gas pressure calibration
Normal
Selector 4
This allows you to select the minimum time that must
pass between two ignitions of the burner in c.h. function.
ON (1)
30 sec.
OFF (0)
This pressure is maintained at the injectors until ignition
occurs (ionization signal from the full sequence ignition
device).
To carry out the adjustment move the function selector
3 to the OFF position (Fig. 33) and use the adjustment
device ”11” (ACC).
Adjust the gas pressure at the injectors to the value indicated in the tables of the User/Installation manual
(Technical information section, Gas pressures at the
burner table).
By rotating the device clockwise the pressure increases.
Check the regular ignition of the burner by turning the
boiler on and off repeatedly.
After the adjustment operations bring the selector 3
back to the normal position (ON).
9.8
n
Check that the fuse is complete
If the Electronic control p.c.b. does not supply any device (pump, fan, etc.) check that the fuse 14 (Fig. 28) is
complete.
If the fuse has blown replace it with one that has the
same characteristics after having identified the reason
for failure.
n
Check the setting jumpers position
3 min.
9.10
Refer to Fig. 35 for the position of the jumpers.
The numbers refer to the marking printed on the circuit
board.
Removal of the electronic control p.c.b
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
Setting jumpers
1
2
3
12 3456 789
Checks
Two setting jumpers must be fitted on the Electronic
control p.c.b. as shown in Fig. 35 and NO TAG.
Two setting jumpers are fitted on the Electronic control
p.c.b.
Fig. 35
Max c.h. power adjustment
By using device 12 (Fig. 28) marked “RISC.” on the
Electronic control p.c.b., you can limit the maximum
useful output delivered during the c.h. operating mode.
This adjustment does not influence the maximum useful output delivered during the d.h.w. operating mode.
By rotating the device clockwise the pressure increases.
Fig. 34
9.6
Ignition gas pressure adjustment
By using the device ”11” (Fig. 28) marked “ACC.” on
the Electronic control p.c.b., it is possible to adjust the
gas pressure at the injectors in the ignition phase.
9.9
Fig. 33
f
9.7
Gain access to the parts located inside the control panel as explained in the section 2.3 of this
manual.
Remove all the wiring connected to the Electronic
control p.c.b..
To disconnect the connectors J1, J2 and J3 (13,
2 and 1 in Fig. 28) delicately flex the hook present
on one side of each socket.
Remove the spindles of the c.h. and d.h.w. temperature adjustment knobs by delicately pulling
them with pliers in the direction shown by the
arrow in Fig. 36.
21
Electronic control p.c.b.
sure of the contact between the boiler reset button B and the tab C (Fig. 37).
Fig. 36
4
5
6
Unscrew the four screws that hold the Electronic
control p.c.b. on to the control panel.
Remove it by lifting its rear edge and freeing it
from any of the wiring.
Re---assemble the Electronic control p.c.b. following the removal procedures in the reverse
order.
Important
A
8
9
22
Fit the p.c.b. into the control panel by first inserting the front lower edge under the control knob
shafts. Lower the rear edge and ensure that no
wiring is trapped beneath.
Insert the spindles in the control panel knobs untill the notch A (Fig. 37) reaches the potentiometer edge. It is not necessary to force them in
the knob.
While tightening the screws that fix the Electronic
control p.c.b. on the control panel, keep the
p.c.b. towards the control panel fascia making
C
Fig. 37
Attention
After installing the Electronic control p.c.b. :
10
Make sure the c.h. ( ) and d.h.w. ( ) temperature adjustment knobs can move freely for the
complete range.
If not, remove the spindle again as described at
step 3, turn the knob half a turn and re---insert the
spindle.
11
Operate the boiler and close the gas inlet cock so
that the boiler goes into the safety lock ---out state.
Verify the correct operation of the boiler reset button by pressing and releasing it.
When re---assembling the Electronic control p.c.b.:
7
B
Warning: After cleaning or replacement as
detailed above refer to section Combustion
analysis check in the chapter Maintenance of
the installation instructions manual.
Electronic control p.c.b.
9.11 Thermal control in the ”
” mode
Switch in the
See functioning with the function
control in the
mode
YES
(sec. 9.12)
function mode
Taking
water from the domestic hot
water circuit?
Is primary circuit
temperature higher than that
selected?
YES
NO
Request for heat from
room thermostat?
Circulator off
Operates motorised valve
Ignition device off
NO
NO
YES
Starts the circulator
Operates motorised valve
Supplies the ignition device
Fig. 38
9.12 Thermal control in the ”
” mode
Switch in the
YES
function mode
Taking
water from the domestic hot
water circuit?
NO
Circulator off
Ignition device off
Circulator on
YES
Supplies the ignition device
Is domestic
hot water outlet temperature
lower than that
required?
NO
Ignition device off
Fig. 39
23
10
Full sequence ignition device
10.1
Function
The Full sequence ignition device used on the boiler
carries out the following fundamental functions:
f
does a sequence of operations (ignition cycle)
which lead to the ignition of the gas at the burner
f
checks the presence of the flame during the entire period in which it is activated
f
supplies the fan and checks its functioning by
means of the signal coming from the air pressure
switch.
The Full sequence ignition device is supplied by the
electronic control p.c.b. when the ignition of the burner
is requested.
The Full sequence ignition device has a safety function
and any incorrect interventions or tampering can result
in conditions of dangerous functioning of the boiler.
The Full sequence ignition device can lock the functioning of the boiler (lock state) and stop its functioning up
to the resetting intervention. The lock is signalled by the
lighting of the lock ---out signal lamp and the device can
be reset only by using the boiler reset button placed on
the control panel fascia.
Some components which are connected to the device
can activate the lock state. The causes of a lock state
could be:
f
The intervention of the safety thermostat (overheat of the primary circuit).
f
A fault on gas supply
f
Faulty ignition (faulty ignition electrodes, their wiring or connection).
f
Faulty flame detection (faulty detection electrode,
its wiring or connection).
f
Gas injectors blocked
f
Faulty modulation gas valve (faulty on---off operators or not electrically supplied).
f
Faulty Full sequence ignition device.
With the burner firing, interrupt the gas supply. The Full
sequence ignition device must carry out a complete
ignition cycle and then stop.
By turning the boiler on and off by means of the function
switch the device must not unlock and the burner must
not turn on.
Fan functioning device
n
With the boiler operating and the burner on, open the
negative pressure test point of the Venturi device.
At the moment of opening the burner must turn off.
10.3 Removal
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
Gain access to the parts located inside the control panel as explained in the section 2.3 of this
manual.
2
Remove all the wiring connected to the Full sequence ignition device.
To disconnect the connectors A, delicately flex the
hook present on one side of each socket
(Fig. 40).
3
Unscrew the two screws B that hold the Full sequence ignition device on the panel and remove
the component.
A
B
Other components like the air pressure switch can temporarily stop the ignition of the burner but allow its ignition when the cause of the intervention has stopped.
Fig. 41 shows the sequence of the operations that are
carried out at the start of every ignition cycle and during
normal functioning.
10.2 Checks
n
Lock sequence
Start the boiler until the burner is ignited.
24
B
A
Fig. 40
4
Re---assemble the Full sequence ignition device
following the removal procedures in the reverse
order.
Full sequence ignition device
10.4 Ignition and control sequence
supply from the electronic control circuit
YES
lock memorised?
NO
cancels lock
NO
Air pressure switch at
rest?
YES
starts fan
NO
Air pressure switch at
work?
YES
beginning of wait period
NO
NO
presence of flame?
YES
Air pressure switch at
work?
YES
starts ignition discharges
opens gas valve
beginning of ignition period
NO
end of ignition
period?
NO
YES
NO
flame presence?
YES
closes gas valve
stops fan
interrupts ignition discharges
memorizes lock
turns on lock--- out light
interrupts ignition discharges
gas valve open
reset push--- button
pressed?
YES
closes gas valve
YES
flame presence?
NO
YES
Air pressure switch at
work?
NO
Safety thermostat
opens the circuit?
YES
NO
Fig. 41
25
11
Modulating gas valve
11.1
Function
The Modulating gas valve A in Fig. 42 controls the gas
inflow to the boiler burner.
1
8
7
2
3
6
5
4
Fig. 43
11.3
Adjustment
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
A
1
Remove the front panel of the case.
2
Open the gas valve inlet pressure test point (6 in
Fig. 43) at the valve input, connect a suitable
pressure gauge and check the gas pressure of
the supply network.
3
Remove the gauge and close the pressure test
point 6.
4
Open the gas valve outlet pressure test point (8
in Fig. 43) and connect the gauge;
Remove the protection cap from the mechanical
pressure adjustment components;
5
Fig. 42
By means of an electric command given to the on---off
operators the passage of the gas through the Modulating gas valve can be opened or closed.
By means of an electric command given to the modulation operator the pressure can be varied and therefore
the gas flow rate to the burner (modulation). The modulation operator has mechanical components which
allow the adjustment of the minimum and maximum
pressure exiting the valve.
11.2
Nomenclature of the parts (Fig. 43)
6
Start the boiler at its maximum power.
Operate the boiler in d.h.w. mode or ensure that
the boiler is not range rated if the test is carried out
in c.h. mode.
7
Rotate the maximum gas pressure adjustment (4
in Fig. 43) until you obtain the required pressure
(by rotating clockwise the pressure increases).
Disconnect one of the two connectors (1 in
Fig. 43) or, alternatively, remove the service panel
as explained in the section 2.3 of this manual and
set the dip---switch selector 1 (see section 9.5) to
the OFF position.
Rotate the minimum gas pressure adjustment (2
in Fig. 43) until you obtain the required pressure
(by rotating clockwise the pressure increases).
8
9
1
Modulation operator’s electric connectors
2
Minimum gas pressure adjustment
3
On---off operators
4
Maximum gas pressure adjustment
5
On---off operators electric connector
6
Gas valve inlet pressure test point
12
7
Modulation operator
8
Gas valve outlet pressure test point
Important: after the gas pressure checks and any
adjustment operations, all of the test points must be
sealed.
26
10
11
Turn the boiler off and re---connect the wire to the
modulating operator (or set the dip---switch selector 1 back to the ON position).
Start the boiler and check again the maximum
gas pressure setting.
Turn the boiler off and disconnect the gauge.
Modulating gas valve
11.4
11.6
Checks
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
n
1
2
n
1
2
3
Check the modulation operator coil
Remove the front panel of the case.
Disconnect the connectors B (Fig. 46) from the
modulating operator and measure the electrical
resistance of the coil. Its electrical resistance
value must be approx. 80 W*.
Check the on---off operators coils
Remove the front panel of the case.
Disconnect the electrical connector C (Fig. 46).
Measure the electrical resistance between the
connector pins of the on---off operators as illustrated in Fig. 44.
Upper on---off operator
approx. 6 400 W*
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
Remove the front panel of the case as explained
in the section 2.3 of this manual.
2
Disconnect the connectors B and C (Fig. 46).
3
Turn off the gas supply and disconnect the gas
isolation cock connector from the inlet port of the
gas valve.
4
Unscrew the connectors F and remove the pipe
G
5
Unscrew the screws H and remove the valve.
6
Reassemble the valve carrying out the removal
operations in reverse order.
After any service operation on the components of
the gas circuit check all the connections for gas
leaks.
Lower on---off operator
approx. 920 W*
* at ambient temperature.
Warning: After cleaning or replacement as
detailed above refer to section Combustion
analysis check in the chapter Maintenance of
the installation instructions manual.
Fig. 44
11.5
Removal of the gas valve
Removal of the on---off operators coils
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
2
3
4
Remove the front panel of the case as explained
in the section 2.3 of this manual.
Disconnect the connector D (Fig. 45).
Unscrew the screw E and remove on---off operator coils.
Reassemble the coils carrying out the removal
operations in reverse order.
G
F
B
C
H
D
E
Fig. 46
Fig. 45
27
12
Primary circuit flow switch
12.1
Function
The Primary circuit flow switch (A in Fig. 47) function is
to detect water flowrate through the primary hydraulic
circuit of the boiler.
12.2
Checks
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
n
1
2
3
Mechanical function
Remove the front panel of the case.
Start and stop the boiler either in d.h.w. or c.h.
mode.
Looking through the switch box verify the position
of the shaft B referring to Fig. 49.
Boiler OFF
B
Boiler ON
Fig. 49
A
I
n
Electrical check
It is possible to verify the general operation of the switch
by measuring the electric resistance between the contacts C. and N.O. of the switch.
1
Remove the switch as explained in section 12.3.
2
Measure the electrical resistance between the
tabs marked C. and N.O. (Fig. 50).
The contact must be normally open.
3
Operate the switch by hand and verify that the
contact is now closed.
C
N.O.
Fig. 47
This hydraulic/membrane operated electrical micro--switch device will control the functioning of the ignition
control circuit, providing there is an adequate quantity
and flow of water in the primary circuit. Any failure of the
pump or obstructions in the primary circuit, whilst in
either c.h. or d.h.w. modes, will not allow the device to
operate.
This device is connected to the electronic control p.c.b.
and if, after the pump operates, it does not activate within 20 seconds the control board will indicate that a fault
condition (see section 9.4 of this manual) has occurred.
do not use
Fig. 50
12.3
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
n
1
2
3
4
C
D
n
1
2
3
Fig. 48
28
Removal
Removal of the switch
Remove the front and right hand side panels of
the case.
Remove the fork C (Fig. 48).
Open the box and disconnect the switch.
Re---assemble the parts in reverse order of removal. Refer to Fig. 50 for the correct wiring connectors on the switch
Removal of the membrane
Remove the front and right hand side panels of
the case, turn off the flow and return isolation
valves and empty the primary circuit.
Remove the fork C that holds the micro---switch
housing D (Fig. 48).
Unscrew the four screws E (see Fig. 51) open the
hydraulic operator and remove the membrane F.
F
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
G
E
1
Remove the front and left hand side panels of the
case, turn off the flow and return isolation valves
and empty the primary circuit.
Completely unscrew the connection K, the locknut L (Fig. 53) and remove the expansion vessel
from the top of the boiler.
H
2
Fig. 51
4
Reassemble the parts in reverse order of removal.
L
When assembling the membrane, ensure that its
concave side faces towards the actuator plate G and
the reference indicated aligns with the seat H (see
Fig. 51).
13
Expansion vessel and
temperature---pressure gauge
13.1
Function
The Expansion vessel (I in Fig. 47) function is to allow
for the volume expansion of the c.h. circuit water due
to the temperature rise.
13.2
1
2
K
Fig. 53
3
Checks
Turn off the flow and return isolation valves and
empty the primary circuit of the boiler.
Remove the protective cap J (Fig. 52) from the
valve on the top of the expansion vessel and connect a suitable air pressure gauge.
Re---assemble the parts in reverse order of removal.
13.4
1
Remove the front and right hand side panels of
the case, turn off the flow and return isolation
valves and empty the primary circuit.
Remove the fork M and the probe holder spring
N (Fig. 54).
Squeeze the tabs O to release the temperature--pressure gauge P and remove it.
Re---assemble the parts in reverse order of removal.
2
J
3
4
Fig. 52
3
13.3
Check the pre---load pressure and refer to the
section Expansion vessel in the User manual and
installation instructions for the correct value.
Removal of the temperature---pressure
gauge
O
P
Removal of the expansion vessel
If there is at least 400 mm clearance above the boiler
and the rear exit flue can be easily removed, the expansion vessel can be changed without removing the
boiler.
M
N
Fig. 54
29
14
D.h.w. flow switch, filter and flow
limiter
14.1
Function
The d.h.w. flow switch A in Fig. 55 is a device that generates an electrical signal when hot water is drawn.
14.2
1
2
3
4
5
6
7
8
9
10
Nomenclature and location of parts
(Fig. 57)
Flow switch sensor
Plug
Magnetic ring
Float
Spring
Filter
Body
Spring seat
Flow limiter (M90E.28S optional accessory)
Threaded ring
7
8
9
10
6
A
4
5
3
2
1
Fig. 57
14.3
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
Fig. 55
When the flow rate through the d.h.w. circuit reaches
about 2,5 litres/min’, the float 4 (Fig. 57) is drawn towards the right.
The resulting magnetic field of ring 3 increases and reaches the flow switch sensor 1.
The sensor generates an electrical signal that switches
the boiler d.h.w operation ON.
The state of the sensor is also indicated by means of the
lamp B placed on the sensor body.
Checks
n
1
2
14.4
Flow switch sensor operation
Remove the front panel of the case.
Switch on the boiler and open a d.h.w. tap. The
lamp B (Fig. 56) placed on the sensor body is
switched on when the flow rate reaches about 2,5
litres/min’.
Removal of the flow switch sensor
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
2
C
B
14.5
Fig. 56
Removal of the flow switch group and
d.h.w. circuit filter
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
30
Remove the front panel of the case.
Disconnect the connector C (Fig. 56) and remove
the sensor by pulling it towards the front of the
boiler (the sensor is held in place by means of a
spring).
Remove the front panel of the case and empty the
d.h.w. circuit.
D.h.w. flow switch, filter and flow limiter
2
3
4
5
6
Remove the flow switch sensor (see section
14.4).
Remove the gas valve (see section 11.6).
Unscrew the plug 2 (Fig. 57) and extract the flow
switch group.
To remove the filter from the flow switch group
separate the body 7 from the plug 2 (Fig. 57) by
unscrewing it.
Reassemble the parts following the removing sequence in reverse order.
5
Fit the ring on the spindle of the float in the way
that lights the lamp B.
6
Isolate the boiler from the mains electricity supply
and reassemble the parts following the removing
sequence in reverse order.
B
1
Attention: the ring 3 (Fig. 57) has a magnetic polarity
and must be correctly coupled with the spindle of
the float 4.
To determine the correct orientation of the ring proceed
as follows:
1
Set the function selector of the boiler in stand---by
mode (Fig. 58).
4
3
Fig. 59
14.6
Flow limiter
The M90E.24S model is factory fitted with a 10 litre/min.
flow limiter.
If on the M90E.28S model the flow rate of the d.h.w. circuit is too high, it is possible to limit it by installing a flow
limiter. The following sizes are available:
Nominal flow rate (litres/min)
Colour
10
Yellow
12
Brown
Fig. 58
2
3
4
Restore the mains electricity supply to the boiler.
Waring -- ensure that all the electric parts and
wirings are dry and do not touch other not
mentioned electric parts during the following
operations.
Hold the flow switch sensor 1 and bring the ring
in touch with the sensor as illustrated in Fig. 59.
Observe the lamp B placed on the sensor body
that should light. If not reverse the ring and repeat
the previous operation.
To install the flow limiter:
1
Remove the flow switch group as explained in the
section 14.5.
2
Unscrew the threaded ring 10 (Fig. 57) and remove it from the body 7.
3
Install the flow limiter 9 putting its smaller diameter side towards the threaded ring.
4
Reassemble the group following the above sequence in reverse order.
31
15
Temperature probe
15.2
15.1
Function
n
Temperature---resistance relationship
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
The Temperature probe has the function of converting
the temperature of the water in the hydraulic circuit
where it is installed into an electrical signal (resistance).
The relation between temperature and electrical resistance is stated in Fig. 60.
W 12500
12000
11500
11000
10500
10000
9500
9000
8500
8000
7500
7000
6500
6000
5500
5000
4500
4000
3500
3000
2500
2000
1500
1000
500
Checks
Disconnect the cable from the Temperature probe.
Measure the temperature of the brass group where the
Temperature probe is located and check the electrical
resistance according to the graph in Fig. 60.
15.3
Removal
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
Refer to Fig. 62 for the c.h. Temperature probe
and to Fig. 63 for the d.h.w. Temperature probe.
1
To remove the Temperature probes remove the
front and right hand side panels of the case.
Empty the primary circuit of the boiler.
2
20 25 30 35 40 45 50 55 60 65 70 75 80 85 90 95 100
3
Remove the electric connector of the Temperature probe and unscrew it.
4
Reassemble the Temperature probe carrying out
the removal operations in reverse order.
°C
Fig. 60
On the boiler there are two Temperature probes. One
on the output of the primary heat exchanger (c.h. Temperature probe) A in Fig. 61 and Fig. 62; one on its
input, before the pump (d.h.w. Temperature probe) B in
Fig. 61 and Fig. 63.
A
Fig. 62
A
B
B
c.h.
return
Fig. 61
32
c.h.
flow
d.h.w.
inlet
d.h.w.
outlet
Fig. 63
16
By---pass valve
16.1
Function
16.2
The By---pass valve A in Fig. 64 is located between the
c.h. water flow and return and its function is that of guaranteeing a minimum flow across the primary heat exchanger if the circulation across the c.h. system is completely closed.
The By---pass valve is fitted on the rear side of the diverter group.
Removal
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
Remove all the case panels.
2
Empty the primary circuit of the boiler.
3
Remove the diverter group as described in the
section 8.4 of this manual.
4
Unscrew the connector B and remove the by--pass valve C (Fig. 65).
B
C
Fig. 65
A
Fig. 64
5
Reassemble the by---pass valve as illustrated in
Fig. 65 reversing the order of removal.
33
17
Fan, venturi device and
Air pressure switch
17.1
Between COM or 3 and N.C. or 1 the contact must be
closed (electrical resistance zero).
3
Function
The function of the Fan is to force the products of combustion to the outside air via the flue system.
4
The Fan is supplied by the full sequence ignition device
at the beginning of the ignition cycle.
Connect the black wire (COM or 3) and the brown
wire (N.C. or 1).
Run the boiler (the Fan must run) and check the
the electric resistance between COM or 3 and
N.O. or 2. Between COM or 3 and N.O. or “2 the
contact must be closed (electrical resistance
zero).
Its correct functioning is controlled by means of a system incorporating a built in venturi device (A in Fig. 72)
and an Air pressure switch.
17.2
Checks
N.O.
COM
Check of the fan
n
”L” connection
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
Remove all the case panels and the sealed
chamber lid.
2
Disconnect the connectors B (Fig. 66) and
measure the electrical resistance of the motor
that has to be about:
47 W --- M90E.24S
43 W --- M90E.28S
25 W --- M90E.32S
(at ambient temperature).
N.C.
”H” connection
Fig. 67a
B
C
”H” connection
(not used)
”L” connection
Fig. 68b
F
F
Check of the Air pressure switch operation
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
2
34
2
Remove all the case panels and the sealed
chamber lid.
Disconnect the wires and check the electrical resistance between the connections of the Air pressure switch.
Refer to the Fig. 67a or b in accordance with the
type of air pressure switch used.
Between COM or 3 and N.O. or 2 the contact must be
open.
Check of the venturi device
This test must be carried out with the sealed
chamber closed
1
Fig. 66
n
n
Fig. 69
Remove the caps of the pressure test points located on the top of the boiler and connect a differential pressure gauge (Fig. 69).
Switch on the boiler.
Fan and Air pressure switch
3
Compare the value on the gauge with the following minimum values:
17.4
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
90 Pa (0,9 mbar) --- M90E.24S
100 Pa (1,0 mbar) --- M90E.28S
130 Pa (1,3 mbar) --- M90E.32S
17.3
Inspection and removal of the venturi
device
Removal of the Fan
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
Remove all the case panels, the sealed chamber
lid and the combustion chamber lid.
2
Disconnect the connectors B and the earth connection C (Fig. 66).
3
Disconnect the pipe which connect the venturi
device to the Air pressure switch.
4
Unscrew the screws D and remove the clamp E
(Fig. 70).
1
Remove the fan (section 17.3).
2
Remove the venturi device by unscrewing the
screw G.
3
Inspect the venturi device A and the connection
pipe H. Ensure they are clean.
Re---assemble the parts in reverse order of removal.
4
Warning: After cleaning or replacement as
detailed above refer to section Combustion
analysis check in the chapter Maintenance of
the installation instructions manual.
A
H
E
G
D
Fig. 72
17.5
Fig. 70
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
5
Remove the three screws F (Fig. 66) securing the
Fan to the flue hood and remove the fan.
6
Assemble the fan carrying out the removal operations in reverse sequence.
1
Warning: to correctly connect the venturi device to
the Air pressure switch, refer to Fig. 71.
2
---
+
Removal of the Air pressure switch
3
4
5
Remove all the case panels and the sealed
chamber lid.
Disconnect the wires from the Air pressure
switch.
Remove the pipe from the Air pressure switch.
Unscrew the screws which hold the Air pressure
switch to the frame.
Assemble the Air pressure switch carrying out the
removal operations in reverse sequence.
Warning: to correctly connect the Air pressure
switch, refer to Fig. 71 and Fig. 67a or Fig. 67b for
the correct wiring.
Fig. 71
Warning: After cleaning or replacement as
detailed above refer to section Combustion
analysis check in the chapter Maintenance of
the installation instructions manual.
Warning: After cleaning or replacement as
detailed above refer to section Combustion
analysis check in the chapter Maintenance of
the installation instructions manual.
35
18
Ignition and detection electrodes
18.2
18.1
Function
n
Checks
Check the position of the electrode edges
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
Three electrodes are fitted near the front part of the
burner. The ignition sparks take place between the metallic edges of the ignition electrodes over the central
ramp of the burner during the ignition sequence.
1
The third electrode is the detection electrode and it detects the presence of the flame.
2
Fig. 73 shows the electrodes configuration on the models M90E.24S, M90E.28S.
Remove all the case panels, the sealed chamber
lid and the combustion chamber lid.
Check for the correct distance between the metallic edges of the ignition electrodes (see
Fig. 75).
4 mm
Fig. 74 shows the electrodes configuration on the
model M90E.32S.
Ignition
Detection
Ignition
Male
Female
Fig. 75
3
Check the integrity of the detection electrode and
ensure that its metallic edge is correctly placed
over the ramp of the burner.
n
Check the connection wires.
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
2
Fig. 73
18.3
Detection
Male
2
3
3b
4
Fig. 74
36
Removal
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
Ignition
1
Female
Remove all the case panels, the sealed chamber
lid and the combustion chamber lid.
Check for the integrity of the insulation of wires
which connect the electrodes to the ignition device.
Remove all the case panels, the sealed chamber
lid and the combustion chamber lid.
Disconnect the electrode wires from the full sequence ignition device.
Remove the burner by unscrewing the four
screws placed at the right and left sides of the
burner.
For model M90E.28S and M90E.32S remove also
the plate C (see Fig. 78 on page 38).
Unscrew the screws A (Fig. 76) which hold the
electrodes to the burner.
Two screws are used on the models M90E.24S,
M90E.28S
Three screws, one for each electrode, are used
on the model M90E.32S.
Ignition and detection electrodes
5
6
Extract the electrodes from the burner.
Assemble the electrodes carrying out the removal
operation in reverse order.
Refer to Fig. 73 in order to recognise the electrodes and to correctly connect the wiring.
Note: the metallic edge of the detection electrode is
longer than the one of the ignition electrodes.
Warning: After cleaning or replacement as
detailed above refer to section Combustion
analysis check in the chapter Maintenance of
the installation instructions manual.
A
Fig. 76
37
19
Safety thermostat
19.1
Function
contact must be closed (electrical resistance zero
W).
The safety thermostat A in Fig. 77 is a device that
senses the temperature of the primary circuit water
which flows in the outlet pipe of the primary heat exchanger.
If the temperature control system of the boiler fails and
the temperature of the primary circuit reaches a dangerous temperature, the safety thermostat opens the
electric circuit that supplies the on---off operators of the
gas valve.
19.3
Removal
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
1
1b
Remove all the case panels and the lid of the
sealed chamber.
For model M90E.28S and M90E.32S remove the
screw B and the plate C (Fig. 78).
Consequently, the full sequence ignition device attempts to light the burner and, at the end, locks the
boiler and lights the lock ---out signal lamp.
A
C
B
Fig. 78
2
3
Disconnect the wiring D (Fig. 79).
Remove the spring E which holds the overheat
thermostat on the pipe of the primary heat exchanger and remove it.
D
E
Fig. 77
19.2
Checks
Warning: isolate the boiler from the mains
electricity supply before removing any
covering or component.
n
1
2
n
1
2
38
Overheat temperature value
Set the temperature control knobs to their max.
position and run the boiler in d.h.w. and c.h.
Allow the boiler to reach its maximum operating
temperature (monitor the temperature gauge on
the instrument panel). The boiler should maintain
a temperature below that of the safety thermostat
and no overheat intervention should occur.
Electrical function
Remove all the case panels and the lid of the
sealed chamber.
Disconnect the safety thermostat and check its
electrical function. Normally (no intervention) the
Fig. 79
4
5
Reassemble the overheat thermostat carrying out
the operations in reverse order.
Apply an adequate quantity of heat conducting
compound between the pipe and the thermostat.
Warning: After cleaning or replacement as
detailed above refer to section Combustion
analysis check in the chapter Maintenance of
the installation instructions manual.
Safety thermostat
39
20
Short spare parts list
Key G.C. part no.
Description
1
173---148
173---149
2
169---069
Burner (mod. M90E.24S,)
Burner (mod. M90E.28S)
Burner (mod. M90E.32S)
Injectors for natural gas (mod. M90E.24S)
Injectors for natural gas (mod. M90E.28S)
Injectors for natural gas (M90E.32S)
Injectors for LPG (mod. M90E.24S)
Injectors for LPG (mod. M90E.28S)
Expansion vessel
Main heat exchanger (mod. M90E.24S)
Main heat exchanger (mod. M90E.28S)
Main heat exchanger (mod. M90E.32S)
Fan (mod. M90E.24S,)
Fan (mod. M90E.28S,)
Fan (mod. M90E.32S)
Gas valve
Air pressure switch 0,88---0,74 mbar
(mod. M90E.24S)
Air pressure switch 1,04---0,92 mbar
(mod. M90E.28S)
Air pressure switch 1,38---1,25 mbar
(mod. M90E.32S)
Safety valve
169---070
3
4
E83---121
5
6
7
8
E83---129
169 127
E83---013
Q.ty Manufacturer part no.
1
KI1004 102
1
KI1004 147
1
BI1193 100
12
KI1064 505
14
16
BI1193 500
12
KI1064 506
14
1
BI1172 103
1
BI1202 101
1
BI1202 102
1
BI1222 100
1
BI1366 102
1
BI1366 103
1
BI1376 105
1
BI1193 105
1
KI1267 103
1
BI1366 107
Manufacturer’s reference
Polidoro
Polidoro
CIMM 6 litres
FIME GR02040 39W
FIME GR02045 47W
FIME GR02050 60W
SIT 845 Sigma
Yamatake ---Honeywell C6065
SIT 380 (alternative)
BI1376 104
1
BI1131 100
Watts
Orkly (alternative)
9
10
E83---178
E83---180
E83---181
11
E83---196
E83---197
12
13
E83---142
Combustion chamber side panels
Combustion chamber rear panel
(mod. M90E.24S)
Combustion chamber rear panel
(mod. M90E.28S, M90E.32S)
Combustion chamber front panel
(mod. M90E.24S)
Combustion chamber front panel
(mod. M90E.28S, M90E.32S)
Electronic regulation p.c.b.
Full sequence ignition device
2
1
BI1326 100
BI1326 107
1
BI1326 108
1
BI1326 101
1
BI1366 109
1
1
BI1515 107
BI1305 101
D.h.w. heat exchanger (mod. M90E.24S,)
D.h.w. heat exchanger (mod. M90E.28S)
D.h.w. heat exchanger (mod. M90E.32S)
Pump
Primary circuit flow switch
D.h.w. flow switch
Main. flow switch membrane
Three way diverter valve (electric actuator)
Overheat thermostat
Fuse 1,6 A T
Temperature probe (main or d.h.w. circuit)
Ignition electrode --- left (M90E.24S, M90E.28S)
Ignition electrode --- left (mod. M90E.32S)
Ignition electrode --- right (M90E.24S, M90E.28S)
Ignition electrode --- right (mod. M90E.32S)
Detection electrode (M90E.24S, M90E.28S)
Detection electrode (mod. M90E.32S)
Temperature ---pressure gauge
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
BI1001 101
BI1001 102
BI1161 100
BI1272 100
BI1011 505
BI1091 104
BI1011 103
BI1101 102
BI1172 105
BI1005 105
BI1001 117
BI1123 101
BI1193 102
BI1123 103
BI1193 103
BI1123 102
BI1193 104
BI1475 108
Bertelli & Partners FM30
Honeywell FPLD (alternative)
14
E01---204
E01---205
15
16
17
18
19
20
21
22
23
E00---684
E83---082
E00---688
E83---086
E83---101
169---083
164---026
E83---127
24
E83---126
25
E83---122
26
E83---145
40
WSC --- NFSL 12/5
Elbi
ELTH --- type 261
IMIT
Short spare parts list
2
1
4
3
6
5
7
8
9
10
12
13
9
11
15
14
20
21
22
16
17
23
19
18
24
25
26
41
*1796209165*
17962.0916.5 1704 44A4 UK